Method and device for controlling the motion of one or more collaborative robots

1. A method for controlling one or more collaborative robots, each one of said one or more collaborative robots being mounted on a fixed or movable base and being equipped with: one or more terminal members; a motion controller configured to move, along predetermined directions, said one or more terminal members based on a position of at least a human operator; wherein said method comprises the following iterative steps: determining position coordinates of said human operator; determining position coordinates of each one of said terminal members; for each terminal member determining, as a function of both said position coordinates of said terminal member and said position coordinates of said human operator, a plurality of productivity indices; each productivity index being associated with a respective one of said predetermined directions; each productivity index being indicative of a maximum speed at which a respective terminal member can move, in a respective one of said predetermined directions, at least in case of a presence of said human operator; supplying to said motion controller said productivity indices; activating said motion controller to move, along said predetermined directions, said one or more terminal members based on said productivity indices.

2. The method according to claim 1 , wherein each collaborative robot comprises at least a robotic manipulator provided with a number n of joints; each terminal member being coupled to a respective robotic manipulator; wherein: said determining position coordinates of each one of said terminal members comprises: cyclically reading a linear position or angular position of each joint of a respective robotic manipulator; collecting said linear positions or said angular positions of each joint in a position vector q having n components; and calculating a speed vector {dot over (q)} as a function of said position vector q; said determining position coordinates of said human operator comprises: cyclically determining a number η of points detected on said human operator; and collecting said number η of points in an operator position vector p; said operator position vector p having 3*η components, corresponding to a three position coordinates of a respective point; said determining a plurality of productivity indices comprises: calculating a matrix E(p,q) and a vector f(p,q), wherein: E(p,q)is a matrix of 2*n*η×n size, calculated as a function of both said operator position vector p and said position vector q; f(p,q) is a vector of 2*n*η components; calculated as a function of both said operator position vector p and said position vector q; and determining said productivity indices as a function of said matrix E(p,q) and said vector f(p,q), wherein the relation E(p,q){dot over (q)}≤f (p,q) holds.

4. The method according to claim 1 , wherein said activating said motion controller to move said one or more terminal members based on said productivity indices further comprises one or more of the following: executing a direction of motion or path which is alternative to said predetermined direction; executing a new path with an alternative final position, possibly not known a priori, which is different than said predetermined movement final position; slowing down the motion of said robot; stopping the motion of said robot.

5. The method according to claim 4 , wherein said controller for controlling the motion of one or more robots decides to take said actions on the basis of a priority mechanism that depends on the type of activity that the robot must carry out and/or the type of movement that said terminal member must make and/or a criterion of profitability of the task to be carried out.

6. A device for controlling the motion of one or more collaborative robots, wherein said device comprises means for implementing the method according to claim 1 , said means comprising: at least one vision system adapted to cyclically determining said position coordinates of one or more human operators over time; means for determining said position coordinates of each one of said terminal members; and means for determining said set of productivity indices associated with respective directions of motion of the terminal member of the robot.